Problem downloading videos from icloud to use in imovie

I have been working on a movie in imovie on my ipad. I have been using videos I downloaded from icloud. Everything was going great until yesterday, one of the picture in picture video overlays no longer works. The first frame of the video shows in the bar and the rest of the video is darkened. The video no longer shows up on top of my slide.

This video was saved on icloud. Now, I cannot download other videos from icloud to use in imovie.

I also cannot access the help feature document anymore.

It seems I am having an icloud issue.

Please advise.

Thank you!